1. Field of the Invention
This invention relates to a truss making apparatus. In one of its aspects, the invention relates to an apparatus for making floor trusses from wooden members wherein the apparatus is adjustable to make trusses of different lengths, widths and bracing patters.
2. State of the Prior Art
Wooden trusses for both roofs and floors have been used for making trusses of dimensional lumber and nail or connector plates. The connector or nail plates are made of 14-20 gauge metal sheets from which are punched a multiplicity of closely spaced jagged projections. These projections extend outwardly from a face of the nail plates and are driven into the lumber at the joints to join the lumber together.
Normally, the trusses are assembled on a table, the nail plates are placed over the top of the wooden truss members and driven into the joints. For this purpose, special jigging is available. A gantry roller press is provided to pass over the truss and press the nail plates into place. After one side of the truss is completed, the truss is turned over, the nail plates are placed at the joints of the second side and a roller press is again rolled over the truss to drive the second set of nail plates into the truss members at the joints.
A truss making apparatus for making roof trusses is disclosed in U.S. Pat. No. 3,255,943 issued to Arthur C. Sanford on June 14, 1966. The Sanford apparatus comprises supporting pads which are mounted on rails for adjustable movement along the rails for making different height trusses. The rails themselves are supported on other rails and are mounted for movement toward and away from each other so that different shapes and sizes of trusses can be made.
Black, in U.S. Pat. No. 3,100,301, issued Aug. 13, 1963, and in U.S. Pat. No. 2,996,721, issued Aug. 22, 1961, discloses a truss making apparatus similar to the Sanford apparatus except that the nail plates are pressed into the joints by a hydraulic cylinder from beneath and a pressure plate is positioned over the joint to react to the pressure from the cylinder to press the nail plates on top of the truss into the lumber truss members. In the later Black patent, the trusses are prestressed by urging upper chords toward the lower chords during the joining operation. The resulting truss is somewhat compressed between the top and bottom chords.
Another truss making apparatus is disclosed in the U.S. Pat. No. 3,241,585 to Jureit, issued Mar. 22, 1966. In the Jureit apparatus, the jigs are supported on rails, one of which is adjustable toward and away from the other. The Jureit apparatus as well as the other aforementioned apparatus is generally designed for making roof trusses and is generally not appropriate for making floor trusses.